It is known for conductor bars to be provided with insulation in order to prevent a short circuit and/or an electrical discharge. One known form of insulating consists of wrapping with an insulating tape containing mica, or a mica tape which is impregnated with an impregnating fluid. When the conductor bar is being wrapped with the insulating tape, the insulating tape is unwound from a supply roll. The insulating tape is fed from the supply roll to the conductor bar. The insulating tape is wound onto the conductor bar by a rotary movement of the conductor bar relative to the supply roll. This wrapping method leads to a non-uniform tape thickness, however, which has to be compensated for retrospectively. In addition, the insulating tape is highly loaded while being applied, in order to increase the winding force and to reduce the tape thickness. The high loading on the insulating tape requires reinforcement of the tape, for example with a glass-fiber support material.